Chemical Dissolution Of Ceramics

The parameter k was a function of temperature and acid concentration while the parameter α remained constant.

Chemical dissolution of ceramics.

The dissolution kinetics of tio 2 powders in hf hcl solutions was studied as a function of time temperature and acid concentration. A literature survey indicates that the formation of such ceramics is a three step process. The application of chemical dissolution for removal of sediment covering ceramics of underwater archaeology has been studied. Xrd analysis revealed that there was no change in the crystal structure in all the samples after the acid challenge.

First oxides dissolve in a phosphoric acid or an acid phosphate solution and metal ions are released into the solution. The chemical solubility of lis was significantly lower than that of other glass ceramic blocks. The rate of dissolution was linear with time directly proportional to hf independent of hcl and exhibited an exponential temperature dependence with an activation energy of 74 9 kj mol. However very strong acids or strong bases t end to produce ion exchange reactions and dissolve the structures.

1 5 wt si ha 0 8 wt si ha pure ha. Aluminium or light alloy e g. We propose that the incorporation of silicate ions into ha leads to an increased rate of dissolution of. Aluminium alloy castings which are themselves susceptible to attack by caustic alkali.

Assessment of chemical dissolution method for conservation of underwater archaeological ceramics. Ceramic core materials are selectively dissolved from light metal e g. The first step of this research was analysis and identification of the content of sediment covering ceramics of underwater archaeology using ir spectrophotometer x ray diffractometer and atomic absorption spectrophotometer. Click ceramics generally have good chemical resistance to weak acids and weak bases.

The dissolution kinetics of alumina in aqueous solution was studied in batch and continuous systems. After the test dissolution of the material was confirmed for all glass ceramic blocks. Data were correlated by the kinetic equation c t 1 exp ktα. It is the f ion that causes the actual damage.

American journal of applied chemistry. The application of chemical dissolution for removal of sediment covering ceramics of underwater archaeology has been studied. The aquoions formed from these cations then react with phosphate anions and form a gel of metal hydrophosphates.